Purevax FeLV

Purevax FeLV is a vaccine containing feline leukaemia virus (FeLV) recombinant canarypox virus (vCP97). Purevax FeLV is presented as a suspension for injection.

Purevax FeLV is used to vaccinate cats from the age of eight weeks against feline leukaemia, an illness affecting the immune system caused by a type of virus known as a retrovirus. The vaccine is used to prevent the symptoms of the disease and to prevent FeLV from remaining in the blood.

A 1 ml dose of Purevax FeLV is injected under the skin. The first injection should be given in cats aged at least eight weeks, with a second injection three to five weeks later. Immunity starts at the latest two weeks after the second injection and lasts for a year. The cats should be revaccinated every year.

Purevax FeLV is a vaccine. Vaccines work by priming the immune system (the body’s natural defences) how to defend itself against diseases. Purevax FeLV contains genes from the FeLV sub-group A called env and gag which have been inserted into another vector (carrier) virus called canarypox using ‘recombinant DNA technology’. The canarypox viruses do not spread or multiply in the cat but they do produce proteins from the FeLV genes.

When a cat is given the vaccine, the immune system recognises the FeLV proteins as ‘foreign’ and makes antibodies against them. In the future, the immune system will be able to produce antibodies more quickly when it is exposed to the FeLV. The antibodies will help to protect against the disease caused by the virus. Immunisation against FeLV sub-group A provides full protection against all three sub-groups of the virus: A, B and C.

The effectiveness of Purevax FeLV has been studied in several trials in laboratory conditions where cats were vaccinated and infected with FeLV. In the field, efficacy has been studied in one main study of kittens aged eight weeks or older, in which the effects of Purevax FeLV were compared with those of another vaccine against FeLV. The vaccinated kittens were housed for up to 28 weeks with a group of kittens who were infected with FeLV. In all trials, the main measure of effectiveness was the presence of antibodies against the virus and infectious FeLV in the vaccinated kittens’ blood.

Purevax FeLV vaccine provided protection against FeLV infection. The first evidence of FeLV infection occurred after six weeks in only a few of the kittens vaccinated with Purevax FeLV. Infection was seen from four weeks in non-vaccinated animals.

A temporary small nodule (hard lump) may appear at the site of injection. This usually disappears within one to four weeks. Temporary lethargy (listlessness) and hyperthermia (increased body temperature) may occur for one day, exceptionally for two days. For a full list of all side effects reported with Purevax FeLV, see the Package Leaflet. Purevax FeLV should not be used in pregnant cats.

In case of accidental self-injection seek medical advice immediately and show the Package Leaflet or the label to the doctor.

The Committee for Medicinal Products for Veterinary Use (CVMP) concluded that the benefits of Purevax FeLV exceed the risks for active immunisation of cats eight weeks of age or older against feline leukaemia for the prevention of persistent viraemia and clinical signs of the related disease, and recommended that Purevax FeLV be given a marketing authorisation. The benefit-risk balance may be found in module 6 of this EPAR.

The European Commission granted a marketing authorisation valid throughout the European Union for Purevax FeLV to MERIAL on 13 April 2000. The marketing authorisation was renewed on 18 April 2005. Information on the prescription status of this product may be found on the label/outer package.